A Comparative Study Between Corresponding Structural Geometric Variables Using 2 Commonly Implemented Hip Structural Analysis Algorithms Applied to Dual-Energy X-Ray Absorptiometry Images

Hip structural analysis (HSA) has been developed over 20 yr, applied extensively in research, and has demonstrated useful outcomes associating bone structural geometry with bone fragility (research-HSA or r-HSA). In 2007, Hologic Inc. (Bedford, MA) incorporated HSA with some modifications as an option for Hologic dual-energy X-ray absorptiometry (DXA) scanners (clinical HSA or c-HSA). This brought HSA from the research environment into the clinical environment. This article reports a comparison of r-HSA and c-HSA implementations using DXA scans from a group of 191 females. Bland-Altman plots at the narrow-neck (NN) HSA region indicated higher r-HSA areal bone mineral density (mean difference: 0.27 g/cm2; 21.7% [of mean]); cross-sectional area (0.63 cm2; 18.7%); cross-sectional moment of inertia (0.26 cm4; 11.1%), and section modulus (0.22 cm3; 14.5%) compared with c-HSA. The converse was observed for NN subperiosteal width (−0.09 cm; 3.1%). High linear correlations (r2 > 0.81) were found between r-HSA and c-HSA NN structural geometric outcomes, with the exception of neck shaft angle (r2 > 0.47). As differences were significant (p < 0.001), slopes and intercepts are provided to enable linear transformations from r-HSA to corresponding c-HSA structural geometric data.